The present invention relates to a self-locking safety belt reeling device for the safety belt and a shock-absorbing device acting on the reeling device. The shock-absorbing device is comprised of a return spring and a shock-absorbing spring whereby the return spring has a greater spring force than the shock-absorbing spring. The two springs are arranged in a common spring housing. Inside the spring housing a coupling wheel, which is actuatable as a function of a reeling state of the safety belt, is provided for coupling the shock-absorbing spring and the return spring such that in a first operational state the return spring and the shock absorbing spring together function as a reeling spring and in a second operational state only the shock-absorbing spring functions as a reeling spring. The shock-absorbing device serves to absorb a sudden shock-like coupling effect.
A safety belt reeling device of the aforementioned kind is known from German Offenlegungsschrift 28 03 874. This safety belt reeling device is provided with a return spring which is suspended with one end from the spring housing and with the other end from a coupling wheel which is in the form of a ratchet wheel. This ratchet wheel is freely rotatable about the belt reeling arbor. A second shock-absorbing spring has a reduced spring force compared to the return spring and is connected with one end thereof to the ratchet wheel and with the other end to the safety belt reeling arbor. At the beginning of the withdrawing movement of the safety belt from the safety belt reeling arbor, the return spring and the shook-absorbing spring act as one spring due to their coupling via the freely rotatable ratchet wheel while, at a prescribed state of withdrawal, a further rotation of the ratchet wheel is prevented by a respective control device so that only the shock-absorbing spring acts on the safety belt reeling arbor.
One disadvantage of the known safety belt reeling device is that, when reeling the safety belt onto the safety belt reeling arbor, at a prescribed reeling state the action of the return spring is added via the control device to the spring force of the shock-absorbing spring which has been acting by itself during the initial reeling process so that the return spring with its stronger spring force suddenly acts on the shock-absorbing spring and forces it into a compact block because the windings of the shock-absorbing spring are suddenly tightly forced onto one another due to the sudden shock-like action of the return spring. The known safety belt reeling device is already provided with an expensive dampening means comprised of a plurality of components in order to avoid this sudden reeling shock.
It is an object of the present invention to improve the safety belt reeling device of the aforementioned kind such that the dampening means is of a simpler construction and functions more effectively.